Emacs（TeX）：如何搜索和替换整个区域？

Question

I bother you to have some tips for this problem: I'm working in Latex with a very dirty code, generated by writer2latex (quite good programme, anyway) and, using Emacs, I'm trying to query-replace multiple lines of code, for instance:

{\centering   [Warning: Image ignored] % Unhandled or unsupported graphics:
%\includegraphics[width=11.104cm,height=8.23cm]{img34}

have to become:

\begin{figure}[tpb]
\begin{center}
\includegraphics[width=\textwidth]{img34}

Using Mx re-builder, I found out that I could underline the whole region I need to query-replace with the string: \\{.*centering.* cq cj .*cm] but, if I Mx replace-regexp using this, I only get: Invalid regexp: "Invalid content of \\\\{\\\\}" Any suggestion about how to perform the query? I have a HUGE amount of lines like these to replace... :-)

Answer 1

Make sure the re-syntax is "read", Cc tab . Remove the initial backslash. Now the regexp should work if you yank it into replace-regexp

Answer 2

You're getting this error message because in Emacs' regular expressions the curly braces \\{ and \\} have special meaning. These braces are used to specify that the part of the regexp immediately before the braces should be matched a certain number of times.

From the GNU Emacs documentation on regexps:

\\{n\\} is a postfix operator specifying n repetitions [...]

\\{n,m\\} is a postfix operator specifying between n and m repetitions [...]

If you want your regexp to actually match a curly brace, do not escape it with a leading slash:

{.*centering.* Cq Cj .*cm]

In order to use a backslash in the replacement string you have to escape it with another backslash. (When doing this in code, it quickly becomes quite ugly because inside a double-quoted string backslashes themselves have to be escaped already. However, since you are doing your replacements interactively, the double escaping is not necessary and thus two backslashs are enough.)

MC-% {.*centering.* Cq Cj .*cm] RET \\\\begin{figure}[tpb] Cq Cj \\\\begin{center} Cq Cj \\\\includegraphics[width=\\\\textwidth] RET